1. Field of the Invention
The present invention relates to an electrostatic recording apparatus and more particularly to an electrostatic recording apparatus wherein a cleaning member is arranged on a recording apparatus and in which an electrostatic latent image is formed on a moving image forming member with the use of an electrostatic recording head.
2. Description of the Prior Art
Heretofore, in recording apparatus in which an electrostatic latent image is formed on the image forming member (e.g. a photosensitive drum covered by the photosensitive substance for electrostatic recording) with the use of an electrostatic recording head (e.g. optical fiber tube (OFT) etc.), the electrostatic latent image formed on the image forming member is generally developed with the use of toner, and the resulting toner image is transferred to the transferrinng medium (e.g., an ordinary sheet of paper). Additionally, as an image forming member, one with the form of an endless belt covered by aforesaid photosensitive substance is used.
As a photosensitive substance, selenium, zinc oxide, cadmium sulfide and organic photoconductive material placed respectively on the electrically conductive support by an appropriate method are used, and as this photosensitive substance, not only photoconductive material but also a dielectric substance made of insulating material are used. The typical apparatus and its process will be described with the aid of FIG. 1. In FIG. 1, the numeral 1 is a photosensitive drum, and the photosensitive layer 2 for electrostatic recording is vaporized or is spread on the surface thereof. This photosensitive drum 1 rotates clockwise and the photosensitive layer 2 is evenly charged by the corona charger 3. In case the photosensitive layer 2 is selenium, it is charged positively by the charger 3. The photosensitive layer 2 thus charged passes the OFT scanning face 4 upon rotation of the photosensitive drum 1. The OFT scanning face 4 lies opposite the photosensitive layer 2 with a very narrow clearance of about 100-500 .mu.m. The area on the photosensitive layer that receives the light from the OFT scanning face loses the charges on its surface and an electrostatic latent image is formed on the photosensitive layer. The photosensitive layer 2 having an electrostatic latent image thereon passes the developing device 5 upon rotation of the photosensitive drum 1. The toner is brought into contact with the electrostatic latent image, so that a toner image (a visible image) may be formed.
The recording sheet P fed at the same speed as the moving speed of the photosensitive layer 2, on the other hand, contacts the photosensitive layer 2 near the charger 6 for transferring, and after a toner image is formed on the photosensitive layer 2 is transferred onto the recording sheet P; the latter is detached from the drum 1 by the charger 7 and then is fed to the fixing device (not illustrated). The photosensitive layer 2 loses most of the adhering toner at the transferring step and a small amount of toner not transferred still remains thereon. The photosensitive layer 2 having this remaining toner thereon passes the neutralizer 8 upon further rotation of the photosensitive drum 1, thereby the remaining toner loses its electrostatic adhesive power and it is cleaned by passing the next cleaning device 9. The photosensitive layer 2 thus cleaned again passes the charger 3 thereunder to be evenly charged at its surface and at the OFT scanning face, the electrostatic recording is made and the above-mentioned cycle is repeated. In the cleaning device, a fur brush, a roller blade and a web etc. are put to practical use as a cleaning means. In case an OFT or the like is used as an electrostatic recording head, the OFT scanning face is opposed to the photosensitive layer with a very narrow clearance as stated before in order to obtain the clear image with no blur. Accordingly, even a small amount of toner tends to adhere electrostatically and physically when passing the OFT scanning face and even a small amount of remaining toner adheres and is accumulated on the OFT scanning face after using the apparatus for the long time, and therefore image information on the OFT scanning face becomes hard to be projected onto the surface of the photosensitive layer, and in the worst case it becomes impossible to be projected, resulting in an extreme disturbance of the aforesaid formation of the latent image. Therefore, on an electrostatic recording apparatus wherein an electrostatic recording head such as an OFT or the like is used, how to clean the head portion and how to keep it clean will be a big problem to be solved. The most sure way for the removal of the adhering toner is to wipe off the OFT scanning face directly and it has been the conventional way to wipe off the OFT scanning face after removing the OFT from the recording position, since the surface of the OFT scanning face is a ground glass. The photosensitive layer is damaged very easily and the clearance between the OFT scanning face and the photosensitive layer is very narrow as stated before. However, a complicated mechanism is needed for removing the OFT from the recording position and further it has drawbacks that a great effort is needed to keep the clearance between OFT and photosensitive layer constant with accuracy.